A conventional connector is fixed on a printed circuit board and connects a printed circuit board to a flexible substrate such as a FFC or FPC. The connector has a zero insertion force (ZIF) structure that is useful for bendable, flexible substrates. The flexible substrate can be inserted into the connector with a low insertion force without sustaining contact pressure from the contacts of the connector. After the flexible substrate is inserted into the connector, contact pressure is placed on the flexible substrate by the contacts of the connector to provide a stable electrical connection.
Japanese Patent Application No. 2000-372875 for “CONNECTOR FOR CONNECTING WITH FLEXIBLE SUBSTRATES” (hereinafter “JP '875”), which is incorporated herein by reference in its entirety, discloses a conventional ZIF connector for connecting flexible substrates to printed circuit boards.
The ZIF structure of a conventional connector 101 is shown in FIG. 11. An end of a flexible substrate 120 is inserted into a recessed insertion opening 107 in a housing 102 of the connector 101. Contacts 105, 106 are fixed at predetermined intervals in housing 102 and include contact points 105a, 106a, respectively. The contact points 105a, 106a face each other and contact the corresponding conductor patterns on the flexible substrate 120 during insertion of the flexible substrate 120 into the insertion opening 107.
A slider 103 moves freely between a backward position and a forward position during operation of the connector 101. The slider 103 is in the backward position when it has been pulled out from the insertion opening 107, and a resulting gap allows for the insertion of the flexible substrate 120 into the insertion opening 107. The slider 103 is in the forward position when it is secured to the housing 102. When the slider is in the forward position, the flexible substrate 120 is inserted into the insertion opening 107 and can contact either contact points 105a or 106a elastically. An insertion slot is located on the bottom side of slider 103 and allows the flexible substrate 120 to be inserted into the insertion opening 107.
A sliding slot 111 on each side of the housing 102 engages with tabs that are located on the sides of the slider 103 and prevents the slider 103 from separating from the housing 102 during operation.
A pressure plate 108 extends outward from the slider 103. When the slider 103 is in the forward position, the pressure plate 108 elastically pushes the end of the flexible substrate into electrical contact with the contacts 105, 106.
An operational lever 104 is supported to rotate with respect to the housing 102 on pivots 112 that extend from turn arms 110. The pivots engage loosely with the pivot-supporting holes 113 that are located on the housing 102. Cam surfaces 115, 116 provided on the operational lever 104 engage with respective follower surfaces on the slider 103 and allow the slider 103 to move between the forward and the backward positions. The slider 103 switches between these two positions by operating the operational lever 104.
The contacts 105, 106 are positioned in a staggered pattern in the housing 102. The contact points 105a, 106a align within the insertion opening 107 along a front and a rear row, respectively.
In JP '875, an operational space on both sides of the housing 102 is unnecessary since the operational lever 104 can turn without blocking the flexible substrate 120.
The thickness of the pressure plate 108 on the slider 103 may be adjusted to allow the flexible substrate 120 to connect elastically with the contacts 105, 106 under sufficient pressure.
The operational lever 104 is prevented from turning unintentionally since it can be locked to the housing 102. Furthermore, unintentional extraction of the flexible substrate 120 can be prevented by the slider 103.
The cam surfaces 115, 116 may be machined easily since the operation lever 104 and the slider 103 interact simply by bringing the cam surfaces 115, 116 in contact with the slider 103. Additionally, a small force is required to turn the operation lever 104 and move the slider 103 since the cam surfaces 115, 116 are adjacent to the rotation center of the operation lever 104.
JP '875 provides an appropriate size of the connector in order to support the operation lever, sufficient contact pressure between the contacts and the flexible substrate, and a stopper to prevent unintentional turning of the operation lever.
However, the area surrounding the pivot-supporting holes 113 is too weak for a small connector 101. The operation lever 104 turns by means of pivots which protrude from turn arms of the operation lever 104. The pivots are loosely engaged in the pivot-supporting holes 113 provided on the housing 102. When the operation lever 104 is mishandled, the areas surrounding the pivot-supporting holes 113 break, and the connector 101 becomes inoperable.
The operation lever 104 turns when the flexible substrate 120 is mounted on the connector 101, and the contacts 105, 106 contact the flexible substrate 120. However, there is no feedback to the operator to indicate when the operation lever 104 has turned or when the operation lever 104 is parallel with the top surface of the housing 102.
Furthermore, vibration may cause the operation lever 104 to release the flexible substrate 120 from the contacts 105, 106, thereby risking a loss of electrical contact since the operation lever 104 is not secured at the position where it is parallel to the housing 102.